Fluid sensitivity evaluation method of tight sandstone reservoir and related equipment

Abstract

The invention discloses a fluid sensitivity evaluation method for a tight sandstone reservoir and related equipment, relates to the field of petroleum and natural gas development, and mainly aims to solve the problems that factors considered by an existing method for evaluating the fluid sensitivity of the tight sandstone reservoir are not comprehensive enough, and an evaluation result is not accurate enough. The method comprises the steps that target samples are determined, and the target samples are an artificial sand-laid fractured rock core, a natural fractured rock core and a base block rock core which are connected in series; determining the recovery ratio before fluid invasion and the recovery ratio after fluid invasion of the target sample; and determining the fluid sensitivity based on the recovery ratio before fluid invasion and the recovery ratio after fluid invasion. The method is used for the fluid sensitivity evaluation process of the tight sandstone reservoir.

Description

Technical Field

[0001] The invention relates to the field of oil and natural gas development, and in particular to a fluid sensitivity evaluation method for a tight sandstone reservoir and related equipment. Background Art

[0002] During the exploration and development of gas reservoirs, the foreign sensitive liquids in drilling, completion and other operations have different mineralization and pH values. After contacting the reservoir rock, they are easy to induce reservoir damage, reduce the reservoir permeability, and lead to a decrease in reservoir recovery. At present, the evaluation of tight sandstone gas reservoir damage is mostly based on the industry standard SY / T 5358-2010 "Reservoir Sensitivity Flow Experiment Evaluation Method", which stipulates the basic methods of water sensitivity, salt sensitivity, acid sensitivity, and alkali sensitivity experimental evaluation. By simulating the invasion of foreign fluids into the formation, this method uses the permeability damage rate before and after the fluid invasion as an evaluation index, but still does not consider the original temperature, overburden formation pressure and the state of gas under original conditions, and cannot simulate the process of depletion exploitation of tight sandstone gas reservoirs, cannot establish a good relationship with the reservoir recovery rate, and cannot obtain more accurate evaluation results. Summary of the invention

[0003] In view of the above problems, the present invention provides a fluid sensitivity evaluation method and related equipment for tight sandstone reservoirs, the main purpose of which is to solve the problem that the current evaluation method for fluid sensitivity of tight sandstone reservoirs does not consider comprehensive factors and the evaluation results are not accurate enough.

[0004] In order to solve at least one of the above technical problems, in a first aspect, the present invention provides a method for evaluating fluid sensitivity of a tight sandstone reservoir, the method comprising:

[0005] Determine the target sample, wherein the target sample is the artificial sand-covered fracture core, the natural fracture core and the base block core connected in series;

[0006] Determine the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample;

[0007] The fluid sensitivity is determined based on the recovery rate before fluid invasion and the recovery rate after fluid invasion. Optionally, the above determination of the recovery rate before fluid invasion and the recovery rate after fluid invasion of the target sample includes:

[0008] Determining the methane content of the target sample in a first state, wherein the first state is a state in which the target sample is fully saturated with methane;

[0009] Determining the methane content of the target sample in a second state, wherein the second state is the state of the target sample after depletion mining;

[0010] The fluid recovery factor before fluid invasion of the target sample is determined based on the methane content of the target sample in the first state and the methane content of the target sample in the second state.

[0011] Optionally, the fluid recovery factor before invasion of the target sample based on the methane content of the target sample in the first state and the methane content of the target sample in the second state includes:

[0012] The recovery factor R before fluid invasion of the target sample is determined based on the following formula: f :

[0013]

[0014] In the above formula, the above Q f1 is the methane content of the target sample in the first state, and the Q f2 is the methane content of the target sample in the second state.

[0015] Optionally, the above-mentioned determination of the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample includes:

[0016] Reversely pumping the sensitive liquid into the target sample for a preset time;

[0017] Based on the flowback pressure difference value, using methane to positively displace the sensitive liquid in the target sample;

[0018] When all the sensitive liquid in the target sample is discharged, the target sample is fully saturated with methane, wherein the state in which the target sample is fully saturated with methane is a third state;

[0019] Determining the methane content of the target sample in a fourth state, wherein the fourth state is a state after depletion mining in the third state;

[0020] The post-fluid invasion recovery factor of the target sample is determined based on the methane content of the target sample in the third state and the methane content of the target sample in the fourth state.

[0021] Optionally, determining the fluid invasion recovery factor of the target sample based on the methane content of the target sample in the third state and the methane content of the target sample in the fourth state includes:

[0022] The recovery factor R after fluid invasion of the target sample is determined based on the following formula: E :

[0023]

[0024] In the above formula, the above Q E1is the methane content of the target sample in the third state, and the Q E2 is the methane content of the target sample in the fourth state.

[0025] Optionally, the above method further includes:

[0026] The above-mentioned backflow pressure difference value P is determined based on the following formula b :

[0027] P b =(P p -P f )×l / L+P r

[0028] In the above formula, the above P p is the reservoir pore pressure, the above P f is the reservoir bottom hole flowing pressure, the above l is the length of the above target sample, the above L is the width of the pressure drop funnel formed after the tight sandstone reservoir is opened, and the above P r For back pressure.

[0029] Optionally, the determination of fluid sensitivity based on the recovery factor before fluid invasion and the recovery factor after fluid invasion includes:

[0030] The fluid sensitivity I is determined based on the following formula:

[0031]

[0032] In the above formula, the above R f is the recovery factor before the above fluid invasion, and the above R E is the recovery factor after the above fluid invasion.

[0033] In a second aspect, an embodiment of the present invention further provides a fluid sensitivity evaluation device for a tight sandstone reservoir, comprising:

[0034] The first determination unit is used to prepare a target sample, wherein the target sample is a series of artificial sand-covered fracture cores, natural fracture cores and matrix cores;

[0035] A second determination unit is used to determine the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample;

[0036] The third determining unit is used to determine the fluid sensitivity based on the recovery factor before the fluid invasion and the recovery factor after the fluid invasion.

[0037] In order to achieve the above-mentioned purpose, according to the third aspect of the present invention, a computer-readable storage medium is provided, wherein the above-mentioned computer-readable storage medium includes a stored program, wherein when the above-mentioned program is executed by a processor, the steps of the above-mentioned fluid sensitivity evaluation method for tight sandstone reservoirs are implemented.

[0038] In order to achieve the above-mentioned purpose, according to the fourth aspect of the present invention, there is provided an electronic device, comprising at least one processor and at least one memory connected to the above-mentioned processor; wherein the above-mentioned processor is used to call the program instructions in the above-mentioned memory to execute the steps of the above-mentioned method for evaluating the fluid sensitivity of tight sandstone reservoirs.

[0039] Through the above technical scheme, the fluid sensitivity evaluation method and related equipment of tight sandstone reservoirs provided by the present invention solve the problem that the factors considered by the current evaluation method of tight sandstone reservoirs for fluid sensitivity are not comprehensive enough and the evaluation results are not accurate enough. The present invention determines the target sample, wherein the target sample is the artificial sand-paved fracture core, natural fracture core and base block core connected in series; determines the recovery rate before fluid invasion and the recovery rate after fluid invasion of the target sample; and determines the fluid sensitivity based on the recovery rate before fluid invasion and the recovery rate after fluid invasion. In the above scheme, the gas occurrence state of the tight sandstone gas reservoir is taken into consideration, and the degree of reservoir sensitivity caused by fluid invasion is evaluated by evaluating the gas production capacity of the core before and after fluid damage, forming an evaluation method for fluid sensitivity under in situ conditions of tight sandstone, which provides a basis for the optimization of the protective reservoir sensitivity liquid system of tight sandstone gas reservoirs and the efficient development of reservoirs.

[0040] Correspondingly, the fluid sensitivity evaluation device, equipment and computer-readable storage medium for tight sandstone reservoirs provided in the embodiments of the present invention also have the above-mentioned technical effects.

[0041] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0043] Figure 1 A schematic flow chart of a method for evaluating fluid sensitivity of a tight sandstone reservoir provided by an embodiment of the present invention is shown;

[0044] Figure 2 A schematic diagram showing the composition of a fluid sensitivity detection device provided by an embodiment of the present invention is shown;

[0045] Figure 3A schematic block diagram showing the composition of a fluid sensitivity evaluation device for a tight sandstone reservoir provided by an embodiment of the present invention is shown;

[0046] Figure 4 A schematic block diagram of the composition of an electronic device for evaluating fluid sensitivity of a tight sandstone reservoir provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0047] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0048] In order to solve the problem that the current evaluation method for fluid sensitivity of tight sandstone reservoirs does not consider all factors and the evaluation results are not accurate enough, the embodiment of the present invention provides a method for evaluating fluid sensitivity of tight sandstone reservoirs, such as Figure 1 As shown, the method includes:

[0049] S101, determining a target sample, wherein the target sample is a series of artificial sand-covered fracture cores, natural fracture cores and base block cores;

[0050] Exemplarily, the embodiment of the present application selects downhole cores of dense sandstone gas wells, screens and processes them into artificial sand-paved fracture cores, natural fracture cores, and matrix cores. The above cores are connected in series to form a target sample for simulating the multi-scale mass transfer pathway of dense sandstone. The target sample is placed in a core holder, and a confining pressure pump and a resistance wire wound on the core holder are used to make the core subject to reservoir temperature and reservoir overlying formation pressure conditions. A vacuum pump is used to extract gas from the pipeline and the core holder for 12 hours, and the experimental system is kept in a vacuum condition. It is understandable that the above vacuuming time can be adjusted according to the specific situation. Based on the above operation, the original formation conditions of the core in the reservoir can be restored, including the formation temperature, pressure, and the occurrence state of gas in the core under reservoir conditions.

[0051] It should be noted that the embodiments of the present application are classified according to the level of gas permeability under effective stress and temperature of the reservoir, and the classification standard is: permeability 1mD>K>0.1mD is natural fracture core, and permeability K≤0.1mD is block core; the preparation method of artificial sand-paved fracture core is to create artificial fractures through the Brazilian splitting method, and select appropriate sand-paving concentration and sand-paving type through the on-site sand-paving system; the reservoir temperature and the overlying stratum pressure settings of the reservoir can be obtained according to the on-site closed coring data.

[0052] S102, determining the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample;

[0053] The above-mentioned step S102 includes steps S1021-S1024:

[0054] S1021, the above-mentioned determination of the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample includes:

[0055] S1022, determining the methane content of the target sample in a first state, wherein the first state is a state in which the target sample is fully saturated with methane;

[0056] For example, in the embodiment of the present application, methane gas is introduced into the core holder to make the pore pressure in the target sample reach the reservoir pore pressure. After stabilization for a certain period of time, the target sample is fully saturated with methane. The core holder is analyzed by nuclear magnetic resonance for the methane gas content in the core, that is, the methane content Q of the target sample in the first state is f1 .

[0057] It should be noted that the methane gas must be fully heated to the reservoir temperature by a gas heating device before injection. Based on the above operation, the occurrence state of the gas in the core at the formation temperature can be restored.

[0058] S1023, determining the methane content of the target sample in a second state, wherein the second state is a state of the target sample after depletion mining;

[0059] For example, in the embodiment of the present application, back pressure is set at the outlet of the core holder, and the extraction volume is obtained by exhaustion extraction within the production time. After the extraction is completed, the methane content in the core holder is analyzed by nuclear magnetic resonance, that is, the methane content Q of the target sample in the second state is f2 Since the embodiment of the present application simulates the depletion production process of a tight sandstone gas reservoir, the fluid sensitivity of the reservoir is evaluated more accurately.

[0060] It should be noted that the back pressure setting above simulates the exhaustion-type production process of tight sandstone gas under the difference between reservoir pore pressure and ground pressure, that is, methane gas spontaneously produces cores under the production pressure difference between pore pressure and back pressure. The production pressure difference is the difference between the core pore pressure and the back pressure. By changing the size of the back pressure, the change of production pressure difference caused by different production nozzle systems on site can be simulated. The above production pressure difference is set based on the on-site drainage system, and the above production time is set based on the on-site production daily production curve.

[0061] S1024. Calculate the pre-fluid invasion recovery rate of the target sample based on the methane content of the target sample in the first state and the methane content of the target sample in the second state.

[0062] The above step S1024 includes S10241:

[0063] S10241. The fluid recovery factor before intrusion of the target sample based on the methane content of the target sample in the first state and the methane content of the target sample in the second state includes:

[0064] The recovery factor R before fluid invasion of the target sample is determined based on the following formula: f :

[0065]

[0066] In the above formula, the above Q f1 is the methane content of the target sample in the first state, and the Q f2 is the methane content of the target sample in the second state. f It is a dimensionless quantity.

[0067] The above step S102 also includes S1025-S1029:

[0068] S1025, pumping the sensitive liquid into the target sample in reverse direction for a preset time;

[0069] Illustratively, the embodiment of the present application uses a vacuum displacement pump to evacuate the target sample, and then pumps a sensitive liquid with a mass fraction of 5% Mn2+ added into the core holder in the reverse direction from the outlet end to damage the target sample core. The above damage to the target sample core needs to continue for a certain period of time.

[0070] It should be noted that the duration of the above-mentioned damage target sample core is set based on the time the injected fluid remains underground. The above-mentioned sensitive liquid refers to the drilling and completion fluid, fracturing fluid and other fluids pumped underground during the drilling and completion and fracturing process. These fluids will cause reservoir sensitivity damage after contacting the reservoir, so they are called sensitive liquids. Before being pumped into the core, the above-mentioned sensitive liquid needs to be fully heated to the reservoir temperature by a fluid heating device. Based on the above operation, the occurrence state of gas in the core at the formation temperature can be restored.

[0071] S1026, based on the flowback pressure difference value, using methane to positively displace the sensitive liquid in the target sample;

[0072] For example, by setting a certain backflow pressure difference, methane forward displacement is used to backflow sensitive liquids. Since the embodiment of the present application simulates the depletion-type production process of tight sandstone gas reservoirs, the actual operation process of sensitive liquids being backflowed after intrusion, the fluid sensitivity of the reservoir is more accurately evaluated.

[0073] The above step S1026 includes S10261:

[0074] S10261, determine the return pressure difference value P based on the following formula b , MPa:

[0075] P b =(P p -P f )×l / L+P r

[0076] In the above formula, the above P p is the reservoir pore pressure, MPa; the above P f is the reservoir bottom hole flowing pressure, MPa; the above l is the length of the above target sample, cm; the above L is the width of the pressure drop funnel formed after the tight sandstone reservoir is opened, cm; the above P r is the back pressure, MPa.

[0077] S1027, when all the sensitive liquid in the target sample is discharged, fully saturating the target sample with methane, wherein the state in which the target sample is fully saturated with methane is the third state;

[0078] For example, after the displacement until no liquid flows out in the embodiment of the present application, methane gas is continuously introduced to fully saturate the core with methane for a period of time, and then the outlet of the core holder is closed, and the methane gas content at this time is analyzed by nuclear magnetic resonance, that is, the methane content Q of the target sample in the third state is E1 .

[0079] S1028, determining the methane content of the target sample in a fourth state, wherein the fourth state is a state after depletion mining in the third state;

[0080] For example, a certain back pressure is set at the outlet of the core holder, and exhaustion mining is carried out for a certain period of time. After the gas mining is completed, the methane content Q in the core holder is analyzed by nuclear magnetic resonance. E2 .

[0081] S1029. Determine the post-fluid invasion recovery factor of the target sample based on the methane content of the target sample in the third state and the methane content of the target sample in the fourth state.

[0082] The above step S1029 includes S10291:

[0083] S10291, determine the recovery factor R after fluid invasion of the target sample based on the following formula E :

[0084]

[0085] In the above formula, the above QE1 is the methane content of the target sample in the third state, and the Q E2 is the methane content of the target sample in the fourth state. E It is a dimensionless quantity.

[0086] S103. Determine the fluid sensitivity based on the recovery factor before the fluid invasion and the recovery factor after the fluid invasion.

[0087] The above step S103 further includes S1031:

[0088] S1031, the determination of fluid sensitivity based on the recovery factor before the fluid invasion and the recovery factor after the fluid invasion includes:

[0089] The fluid sensitivity I is determined based on the following formula:

[0090]

[0091] In the above formula, the above R f is the recovery factor before the above fluid invasion, and the above R E is the recovery factor after the above fluid invasion, and I is a dimensionless quantity.

[0092] For example, since the present application does not use permeability as the evaluation standard, but uses the gas recovery rate before and after the invasion of sensitive liquid as the evaluation index to evaluate the sensitivity of the reservoir to the fluid, it is more in line with the actual situation of the mine than the current standard which uses the permeability before and after damage as the evaluation index, and is closely linked to the indoor experiment of fluid sensitivity of tight sandstone gas layers and the well site capacity evaluation.

[0093] Exemplarily, a reservoir fluid sensitivity evaluation standard provided in an embodiment of the present application is shown below:

[0094] When I≤5%, the reservoir fluid sensitivity is zero;

[0095] When 5%<I≤30%, the reservoir fluid sensitivity is weak;

[0096] When 30%<I≤50%, the reservoir fluid sensitivity is moderate to weak;

[0097] When 50%<I≤70%, the reservoir fluid sensitivity is moderate to strong;

[0098] When 70%<I≤90%, the reservoir fluid sensitivity is strong;

[0099] When I>90%, the reservoir fluid sensitivity is extremely strong.

[0100] In summary, the embodiment of the present application first screens and prepares the base block-natural fracture-artificial fracture core, then saturates it with methane gas, and then uses external fluid to reversely invade and damage the core, and evaluates the gas production capacity of the core before and after fluid damage, and then feeds back the degree of reservoir sensitivity caused by fluid invasion. Since the embodiment of the present application takes into account the in situ temperature, overlying formation pressure and the occurrence state of gas under in situ conditions, the process of depletion-type exploitation of tight sandstone gas reservoirs is simulated, and the relationship with reservoir recovery rate is well established, the evaluation method of fluid sensitivity under in situ conditions of tight sandstone formed can provide a basis for the optimization of sensitive liquids for tight sandstone, and ensure the efficient development of tight sandstone gas reservoirs.

[0101] Through the above technical scheme, the fluid sensitivity evaluation method of tight sandstone reservoir provided by the present invention solves the problem that the factors considered by the current evaluation method of tight sandstone reservoir for fluid sensitivity are not comprehensive enough and the evaluation results are not accurate enough. The present invention determines the target sample, wherein the target sample is the artificial sand-paved fracture core, natural fracture core and base block core connected in series; determines the recovery rate before fluid invasion and the recovery rate after fluid invasion of the target sample; and determines the fluid sensitivity based on the recovery rate before fluid invasion and the recovery rate after fluid invasion. In the above scheme, the gas occurrence state of the tight sandstone gas reservoir is taken into consideration, and the degree of reservoir sensitivity caused by fluid invasion is evaluated by evaluating the gas production capacity of the core before and after fluid damage, forming an evaluation method for fluid sensitivity under in situ conditions of tight sandstone, which provides a basis for the optimization of the protective reservoir sensitivity liquid system of tight sandstone gas reservoirs and the efficient development of reservoirs.

[0102] Furthermore, Figure 2 A schematic diagram of the composition of a fluid sensitivity detection device provided by an embodiment of the present invention is shown: wherein 1 is a methane gas cylinder; 2 and 12 are heating devices; 3 and 11 are temperature sensors; 4, 7, 10, and 16 are valves; 5 is a core holder; 6 and 15 are pressure sensors; 8 is a back pressure valve; 9 is a measuring cylinder; 13 is a sensitive liquid container; 14 is a vacuum displacement pump; 17 is a confining pressure pump; and 18 is a nuclear magnetic resonance system.

[0103] For example, the following illustrates a situation in which an embodiment of the present application is implemented:

[0104] S1. First, select the downhole core of a tight sandstone gas well in a certain area, screen and process it into a standard core containing one artificial sand-covered fracture core, one natural fracture core and one base block core, all of which are 3 to 5 cm long and about 2.5 cm wide. Dry the three cores at 60°C for 24 hours, and put them in series into the core holder 5 to form a target sample for simulating the multi-scale mass transfer pathway of tight sandstone. Use a confining pressure pump 17 and a resistance wire wrapped around the core holder to keep the core at a reservoir temperature of 50°C and a reservoir overlying formation pressure of 60MPa. Use a vacuum pump to extract the gas in the pipeline and the core holder for 12 hours to keep the experimental system in vacuum conditions;

[0105] S2. Open valve 4 and close valves 7 and 10. Use methane gas cylinder 1 to introduce methane gas into the core holder 5 until the pore pressure reaches the reservoir pore pressure of 35 MPa. Stabilize for a certain period of time to make the target sample fully saturated with methane. Use nuclear magnetic resonance system 18 to analyze the methane gas content Q in the core of the core holder. f1 (i.e., the methane content of the target sample in the first state);

[0106] S3. At the outlet of the core holder, the back pressure is set to 5 MPa through the back pressure valve 8, and the mining volume is obtained by exhaustion mining within 24 hours. After the mining is completed, the methane content Q in the core holder is analyzed by the nuclear magnetic resonance system 18. f2 (i.e. the methane content of the target sample in the second state), the recovery factor is calculated by the following formula:

[0107]

[0108] In the above formula, the above Q f1 is the methane content of the target sample in the first state, and the Q f2 is the methane content of the target sample in the second state. f It is a dimensionless quantity.

[0109] S4, use the vacuum pump 14 to evacuate the experimental system, then close valves 4 and 7, open valve 10, and pump 5% Mn into the sensitive liquid container 13. 2+ The sensitive liquid enters and damages the core after passing through the heating device for 12 hours;

[0110] S5. Open valves 4 and 7, and close valve 10. Set the backflow pressure difference to 3.5 MPa, use methane positive backflow sensitive fluid, use measuring cylinder 9 to collect liquid, and drive until no liquid flows out. Continue to introduce methane gas for a period of time, close the outlet of the core holder, and use nuclear magnetic resonance to analyze the methane gas content Q at this time. E1 (i.e., the methane content of the above target sample in the third state);

[0111] S6, repeat the steps in S3, and after the mining is completed, analyze the methane content Q in the core holder by the nuclear magnetic resonance system 18 E2 (i.e., the methane content of the target sample in the fourth state), the recovery rate after fluid invasion and flowback is calculated by the following formula:

[0112]

[0113] In the above formula, the above Q E1 is the methane content of the target sample in the third state, and the Q E2 is the methane content of the target sample in the fourth state. E It is a dimensionless quantity.

[0114] S7. Evaluate the sensitivity of the reservoir to the foreign fluid by using the methane recovery rate before and after damage as the evaluation standard. The sensitivity of the reservoir to the foreign fluid is evaluated using the following formula:

[0115]

[0116] In the above formula, the above R f is the recovery factor before the above fluid invasion, and the above R E is the recovery factor after the above fluid invasion, and I is a dimensionless quantity.

[0117] The final experimental results show that the sensitivity of fluid sensitivity caused by external fluid contacting the reservoir is 64%, which is medium to strong.

[0118] Furthermore, as a response to the above Figure 1 In order to realize the method shown in the figure, the embodiment of the present invention also provides another fluid sensitivity evaluation device for tight sandstone reservoirs, which is used to evaluate the fluid sensitivity of the above-mentioned Figure 1 The device embodiment corresponds to the aforementioned method embodiment. For ease of reading, this device embodiment will not repeat the details of the aforementioned method embodiment one by one, but it should be clear that the device in this embodiment can correspond to all the contents of the aforementioned method embodiment. Figure 3 As shown, the device includes: a first determining unit 21, a second determining unit 22 and a third determining unit 23, wherein:

[0119] The first determination unit 21 is used to prepare a target sample, wherein the target sample is a series connection of an artificial sand-covered fracture core, a natural fracture core and a matrix core;

[0120] A second determination unit 22 is used to determine the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample;

[0121] The third determination unit 23 is used to determine the fluid sensitivity based on the recovery factor before the fluid invasion and the recovery factor after the fluid invasion.

[0122] The processor includes a kernel, and the kernel retrieves the corresponding program unit from the memory. One or more kernels can be set, and a fluid sensitivity evaluation method for tight sandstone reservoirs is implemented by adjusting kernel parameters, which can solve the problem that the current evaluation method for tight sandstone reservoir fluid sensitivity does not consider comprehensive factors and the evaluation results are not accurate enough.

[0123] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored program, and when the program is executed by a processor, the fluid sensitivity evaluation method of the tight sandstone reservoir is implemented.

[0124] An embodiment of the present invention provides a processor, and the processor is used to run a program, wherein the fluid sensitivity evaluation method of the tight sandstone reservoir is executed when the program is run.

[0125] An embodiment of the present invention provides an electronic device, the electronic device comprising at least one processor and at least one memory connected to the processor; wherein the processor is used to call program instructions in the memory to execute the fluid sensitivity evaluation method for tight sandstone reservoirs as described above

[0126] An embodiment of the present invention provides an electronic device 30, such as Figure 4 As shown, the electronic device includes at least one processor 301, and at least one memory 302 and a bus 303 connected to the processor; wherein the processor 301 and the memory 302 communicate with each other through the bus 303; the processor 301 is used to call the program instructions in the memory to execute the above-mentioned fluid sensitivity evaluation method of the tight sandstone reservoir.

[0127] The intelligent electronic devices in this article can be PCs, PADs, mobile phones, etc.

[0128] The present application also provides a computer program product, which, when executed on a process management electronic device, is suitable for executing a program that initializes the steps of the above-mentioned method for evaluating fluid sensitivity of tight sandstone reservoirs.

[0129] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0130] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0131] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0134] The present application also provides a computer program product, which includes computer software instructions. When the computer software instructions are executed on a processing device, the processing device is caused to execute the following Figure 1 This corresponds to the flow of control of the memory in the embodiment.

[0135] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a server or a data center that includes one or more available media integration. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state drive (SSD)), etc.

[0136] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0137] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0138] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0139] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0140] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

[0141] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for evaluating fluid sensitivity of a tight sandstone reservoir, characterized in that: include: Determine a target sample, wherein the target sample is a series-connected artificial sand-covered fracture core, a natural fracture core, and a matrix core; Determine the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample; The fluid sensitivity is determined based on the pre-fluid invasion recovery factor and the post-fluid invasion recovery factor.

2. The method according to claim 1, characterized in that The step of determining the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample comprises: Determining the methane content of the target sample in a first state, wherein the first state is a state of being fully saturated with methane in the target sample; Determining the methane content of the target sample in a second state, wherein the second state is the state of the target sample after depletion mining; A fluid recovery factor before fluid invasion of the target sample is determined based on the methane content of the target sample at the first state and the methane content of the target sample at the second state.

3. The method according to claim 2, characterized in that The fluid recovery factor before intrusion of the target sample based on the methane content of the target sample in the first state and the methane content of the target sample in the second state includes: The recovery factor R before fluid invasion of the target sample is determined based on the following formula: f : In the above formula, Q f1 is the methane content of the target sample in the first state, and the Q f2 is the methane content of the target sample in the second state.

4. The method according to claim 1, characterized in that: The step of determining the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample comprises: Reversely pumping the sensitive liquid into the target sample for a preset time; Based on the flowback pressure difference value, using methane to positively displace the sensitive liquid in the target sample; When all the sensitive liquid in the target sample is discharged, the target sample is fully saturated with methane, wherein the state in which the target sample is fully saturated with methane is a third state; Determining the methane content of the target sample in a fourth state, wherein the fourth state is a state after depletion mining is performed in the third state; The post-fluid invasion recovery factor of the target sample is determined based on the methane content of the target sample at the third state and the methane content of the target sample at the fourth state.

5. The method according to claim 4, characterized in that The determining the post-fluid invasion recovery factor of the target sample based on the methane content of the target sample in the third state and the methane content of the target sample in the fourth state comprises: The recovery factor R after fluid invasion of the target sample is determined based on the following formula: E : In the above formula, Q E1 is the methane content of the target sample in the third state, and the Q E2 is the methane content of the target sample in the fourth state.

6. The method according to claim 4, characterized in that Also includes: The backflow pressure difference value P is determined based on the following formula b : P b =(P p -P f )×l / L+P r In the above formula, the P p is the reservoir pore pressure, the P f is the reservoir bottom hole flowing pressure, l is the length of the target sample, L is the width of the pressure drop funnel formed after the tight sandstone reservoir is opened, and P r For back pressure.

7. The method according to claim 1, characterized in that The determining of fluid sensitivity based on the recovery factor before fluid invasion and the recovery factor after fluid invasion comprises: The fluid sensitivity level I is determined based on the following formula: In the above formula, R f is the recovery factor before fluid invasion, and R E is the recovery factor after the fluid invasion.

8. A fluid sensitivity evaluation device for tight sandstone reservoirs, characterized in that: include: A first determination unit is used to prepare a target sample, wherein the target sample is a series of artificial sand-covered fracture cores, natural fracture cores and matrix cores; A second determination unit is used to determine the recovery factor before fluid invasion and the recovery factor after fluid invasion of the target sample; The third determining unit is used to determine the fluid sensitivity based on the recovery factor before fluid invasion and the recovery factor after fluid invasion.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed by a processor, the method for evaluating fluid sensitivity of a tight sandstone reservoir according to any one of claims 1 to 8 is implemented.

10. An electronic device, characterized in that: The electronic device includes at least one processor and at least one memory connected to the processor; wherein the processor is used to call program instructions in the memory to execute the fluid sensitivity evaluation method for tight sandstone reservoirs according to any one of claims 1 to 8.

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